Who are Four of Diamonds?

The four piece are made up of Caroline, Sophia, Yasmin and Lauren and Nicole Scherzinger named them as her favourite girl-group in the competition at their first audition.

4 OF DIAMONDS

The girls had only been performing together as a group for a few weeks before they initially auditioned for the judges. They describe their sound as a modern twist on the classic sixties style.

Each of the girls hails from a different part of the UK; Caroline (19) is from London and has been studying Commercial Music at University; Lauren (21) is from Surrey and has been working part-time in a supermarket and teaching dance; Yasmin (17) from Manchester has been studying a music course and Sophia (19) from Birmingham has been studying Bio-Veterinary Science at University.

Speaking about his decision to bring them back, Louis Walsh, who is mentoring the groups, said: "I was really impressed with the girls at Judges’ Houses but only had three spots to fill for the Live Shows.

"At the time a lot of viewers were disappointed that I didn’t put the girls through, now that a place has opened up in my category, I’ve listened to the fans and am delighted to be bringing the girls back. They're a great girl group and I'm hoping will take me all the way to the final."

Speaking about their return to the show, Four Of Diamonds said: "We are so excited to be back on The X Factor ­we’re really looking forward to performing live, working hard and showing everyone what we’re made of."

Chatting on the show back at judges' houses, the girls reflected: "The six chair challenge was quite brutal wasn't it? We were so nervous the whole time. I remember shaking and thinking, 'This could be the end of the road.'.

"Every minute of it was worth it and we nailed it, we're here!"

Before singing for Louis, 4 of Diamonds told cameras: "We've been rehearsing non-stop, 10-6 every day. We've not partied. We've worked so hard and we hope Louis can see it.

"We're all feeling really nervous. Each stage we get to we want it more and more.

"We're going to do everything we can to take one of those three places."

Saying they wanted to put a 60s twist on the 90s girl band, 4 of Diamonds performed an amazing arrangement of Lorde's Royals.

Now they're set to make their live show debut this Saturday night on ITV from 8PM.